1. Field of the Invention
This invention relates to a modulation method. This invention also relates to a radio communication system.
2. Description of the Related Art
Japanese published unexamined patent application 9-93302 discloses a digital radio communication system in which a transmitted signal is composed of a stream of frames each having N successive symbols. Here, N denotes a predetermined natural number. In every frame, the first and second symbols are pilot symbols of known data (fixed data), and the pilot symbols are followed by (N-2) symbols representing main information to be transmitted.
In the digital radio communication system of Japanese application 9-93302, since pilot symbols in every frame are composed of fixed data and are not used in the transmission of main information, they cause a decrease in the main-information transmission rate.